Problem Description:
An example scenario that involves deferred removal
1. A new base image gets created (e.g. 'docker load -i'). The base device is activated and
mounted at some point in time during image creation.
2. While image creation is in progress, a privileged container is started
from another image and the host's mount name space is shared with this
container ('docker run --privileged -v /:/host').
3. Image creation completes and the base device gets unmounted. However,
as the privileged container still holds a reference on the base image
mount point, the base device cannot be removed right away. So it gets
flagged for deferred removal.
4. Next, the privileged container terminates and thus its reference to the
base image mount point gets released. The base device (which is flagged
for deferred removal) may now be cleaned up by the device-mapper. This
opens up an opportunity for a race between a 'kworker' thread (executing
the do_deferred_remove() function) and the Docker daemon (executing the
CreateSnapDevice() function).
This PR cancel the deferred removal, if the device is marked for it. And reschedule the
deferred removal later after the device is resumed successfully.
Signed-off-by: Shishir Mahajan <shishir.mahajan@redhat.com>
This fix tries to fix logrus formatting by removing `f` from
`logrus.[Error|Warn|Debug|Fatal|Panic|Info]f` when formatting string
is not present.
This fix fixes#23459.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
device Base should not exists on failure:
--- FAIL: TestDevmapperCreateBase (0.06s)
graphtest_unix.go:122: stat
/tmp/docker-graphtest-079240530/devicemapper/mnt/Base/rootfs/a subdir:
no such file or directory
--- FAIL: TestDevmapperCreateSnap (0.00s)
graphtest_unix.go:219: devmapper: device Base already
exists.
it should be:
--- FAIL: TestDevmapperCreateBase (0.25s)
graphtest_unix.go:122: stat
/tmp/docker-graphtest-828994195/devicemapper/mnt/Base/rootfs/a subdir:
no such file or directory
--- FAIL: TestDevmapperCreateSnap (0.13s)
graphtest_unix.go:122: stat
/tmp/docker-graphtest-828994195/devicemapper/mnt/Snap/rootfs/a subdir:
no such file or directory
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
1) docker create / run / start: this would create a snapshot device and mounts it onto the filesystem.
So the first time GET operation is called. it will create the rootfs directory and return the path to rootfs
2) Now when I do docker commit. It will call the GET operation second time. This time the refcount will check
that the count > 1 (count=2). so the rootfs already exists, it will just return the path to rootfs.
Earlier it was just returning the mp: /var/lib/docker/devicemapper/mnt/{ID} and hence the inconsistent paths error.
Signed-off-by: Shishir Mahajan <shishir.mahajan@redhat.com>
For things that we can check if they are mounted by using their fsmagic
we should use that and for others do it the slow way.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This makes sure fsdiff doesn't try to unmount things that shouldn't be.
**Note**: This is intended as a temporary solution to have as minor a
change as possible for 1.11.1. A bigger change will be required in order
to support container re-attach.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Right now there is no way to know what's the minimum free space threshold
daemon is applying. It would be good to export it through docker info and
then user knows what's the current value. Also this could be useful to
higher level management tools which can look at this value and setup their
own internal thresholds for image garbage collection etc.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Since the layer store was introduced, the level above the graphdriver
now differentiates between read/write and read-only layers. This
distinction is useful for graphdrivers that need to take special steps
when creating a layer based on whether it is read-only or not.
Adding this parameter allows the graphdrivers to differentiate, which
in the case of the Windows graphdriver, removes our dependence on parsing
the id of the parent for "-init" in order to infer this information.
This will also set the stage for unblocking some of the layer store
unit tests in the next preview build of Windows.
Signed-off-by: Stefan J. Wernli <swernli@microsoft.com>
Instead of implementing refcounts at each graphdriver, implement this in
the layer package which is what the engine actually interacts with now.
This means interacting directly with the graphdriver is no longer
explicitly safe with regard to Get/Put calls being refcounted.
In addition, with the containerd, layers may still be mounted after
a daemon restart since we will no longer explicitly kill containers when
we shutdown or startup engine.
Because of this ref counts would need to be repopulated.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Instead of implementing refcounts at each graphdriver, implement this in
the layer package which is what the engine actually interacts with now.
This means interacting directly with the graphdriver is no longer
explicitly safe with regard to Get/Put calls being refcounted.
In addition, with the containerd, layers may still be mounted after
a daemon restart since we will no longer explicitly kill containers when
we shutdown or startup engine.
Because of this ref counts would need to be repopulated.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Now what we provide dynamic binaries for all plaforms,
we shouldn't try to run docker without udev sync support.
This change changes the previous warning to an Error,
unless the user explicitly overrides the warning, in
which case they're at their own risk.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Once thin pool gets full, bad things can happen. Especially in case of xfs
it is possible that xfs keeps on retrying IO infinitely (for certain kind
of IO) and container hangs.
One way to mitigate the problem is that once thin pool is about to get full,
start failing some of the docker operations like pulling new images or
creation of new containers. That way user will get warning ahead of time
and can try to rectify it by creating more free space in thin pool. This
can be done either by deleting existing images/containers or by adding more
free space to thin pool.
This patch adds a new option dm.min_free_space to devicemapper graph
driver. Say one specifies dm.min_free_space=10%. This means atleast
10% of data and metadata blocks should be free in pool before new device
creation is allowed, otherwise operation will fail.
By default min_free_space is 10%. User can change it by specifying
dm.min_free_space=X% on command line. A value of 0% will disable the
check.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now if somebody has enabled deferred device deletion, then
deleteTransaction() returns success even if device could not be deleted. It
has been marked for deferred deletion. Right now we will mark device ID free
and potentially use it again when somebody tries to create new container. And
that's wrong. Device ID is not free yet. It will become free once devices
has actually been deleted by the goroutine later.
So move the location of call to markDeviceIDFree() to a place where we know
device actually got deleted and was not marked for deferred deletion.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
The loopback logic is not technically exclusive to the devicemapper
driver. This reorganizes the code such that the loopback code is usable
outside of the devicemapper package and driver.
Signed-off-by: Vincent Batts <vbatts@redhat.com>
After the very first init of the graph `docker info` correctly shows the
base fs type under `Backing Filesystem`. This information isn't stored
anywhere. After a restart (w/o erasing `/var/lib/docker`) `docker info`
shows an empty string under `Backing Filesystem`.
This patch records the base fs type after the first run in the metadata
or, to fix old devices that don't have this info in the metadata, just
probe the fs type of the base device at graph startup.
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
ext4 filesystem creation can take a long time on 100G thin device and
systemd might time out and kill docker service. Often user is left thinking
why docker is taking so long and logs don't give any hint. Log an info
message in journal for start and end of filesystem creation. That way
a user can look at logs and figure out that filesystem creation is
taking long time.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
This change will allow us to run SELinux in a container with
BTRFS back end. We continue to work on fixing the kernel/BTRFS
but this change will allow SELinux Security separation on BTRFS.
It basically relabels the content on container creation.
Just relabling -init directory in BTRFS use case. Everything looks like it
works. I don't believe tar/achive stores the SELinux labels, so we are good
as far as docker commit.
Tested Speed on startup with BTRFS on top of loopback directory. BTRFS
not on loopback should get even better perfomance on startup time. The
more inodes inside of the container image will increase the relabel time.
This patch will give people who care more about security the option of
runnin BTRFS with SELinux. Those who don't want to take the slow down
can disable SELinux either in individual containers or for all containers
by continuing to disable SELinux in the daemon.
Without relabel:
> time docker run --security-opt label:disable fedora echo test
test
real 0m0.918s
user 0m0.009s
sys 0m0.026s
With Relabel
test
real 0m1.942s
user 0m0.007s
sys 0m0.030s
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
If platform supports xfs filesystem then use xfs as default filesystem
for container rootfs instead of ext4. Reason being that ext4 is pre-allcating
lot of metadata (around 1.8GB on 100G thin volume) and that can take long
enough on AWS storage that systemd times out and docker fails to start.
If one disables pre-allocation of ext4 metadata, then it will be allocated
when containers are mounted and we will have multiple copies of metadata
per container. For a 100G thin device, it was around 1.5GB of metadata
per container.
ext4 has an optimization to skip zeroing if discards are issued and
underlying device guarantees that zero will be returned when discarded
blocks are read back. devicemapper thin devices don't offer that guarantee
so ext4 optimization does not kick in. In fact given discards are optional
and can be dropped on the floor if need be, it looks like it might not be
possible to guarantee that all the blocks got discarded and if read back
zero will be returned.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
If user wants to use a filesystem it can be specified using dm.fs=<filesystem>
option. It is possible that docker already had base image and a filesystem
on that. Later if user wants to change file system using dm.fs= option
and restarts docker, that's not possible. Warn user about it.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now if blkid fails we are just logging a debug message and don;t return
the actual error to caller. Caller gets the error message that thin pool
base device UUID verification failed and it might give impression that thin
pool changed. But that's not the case. Thin pool is in such a state that we
could not even query the thin device UUID. Retrun error message appropriately
to make situation more clear.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
